Hi all: I met a question about "lines".
attach(cars) plot(dist ~ speed) #add the regression line to the plot lines(fitted(lm(dist~speed)) ~ speed) plot(dist ~ speed) #what kind of curve does the following command add to the plot? lines(fitted(lm(dist~speed))) My question is : what kind of curve does the last command add to the plot? My guess:maybe the level of fitted values? > range(fitted(lm(dist~speed))) [1] -1.84946 80.73112 But from the plot,I can see the range of the curve is about 10 to 40 more or less,which is different from(-1.84946, 80.73112).So the curve must not be the fitted values.What kind of curve does the last command add to the plot then? Many thanks for your help My best [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.